ExtJs3.4.0 to ExtJs4.1.1 upgrade issues - extjs4

Question

ExtJS4: I am having problems while upgrading my application ExtJs version from 3.4.0 to 4.1.1a.
My 3.4.0 version code:
this.jsonStore = new Ext.data.JsonStore({
proxy : new Ext.data.HttpProxy({
url: 'rs/environments',
disableCaching: true
}),
restful : true,
storeId : 'Environments',
idProperty: 'env',
fields : [
'ConnectionName', 'Type'
]
});
this.colmodel = new Ext.grid.ColumnModel({
defaults: {
align: 'center'
},
columns: [{
header: Accero.Locale.text.adminlogin.connectionsHeading,
width : 140,
dataIndex: 'ConnectionName'
},
{
header: Accero.Locale.text.adminlogin.connectionTypeHeader,
width : 120,
dataIndex: 'Type'
}]
});
config = Ext.apply({
enableHdMenu: false,
border : true,
stripeRows : true,
store : this.jsonStore,
view : new Ext.grid.GridView(),
header : false,
colModel : this.colmodel,
sm : new Ext.grid.RowSelectionModel({singleSelect: true}),
loadMask: {
msg: Accero.Locale.text.adminlogin.loadingmask
}
}, config);
I made below changes to make application work with ExtJs4.1.1:
var sm = new Ext.selection.CheckboxModel( {
listeners:{
selectionchange: function(selectionModel, selected, options){
// Must refresh the view after every selection
myGrid.getView().refresh();
// other code for this listener
}
}
});
var getSelectedSumFn = function(column){
return function(){
var records = myGrid.getSelectionModel().getSelection(),
result = 0;
Ext.each(records, function(record){
result += record.get(column) * 1;
});
return result;
};
}
var config = Ext.create('Ext.grid.Panel', {
autoScroll:true,
features: [{
ftype: 'summary'
}],
store: this.jsonStore,
defaults: { // defaults are applied to items, not the container
sortable:true
},
selModel: sm,
columns: [
{header: Accero.Locale.text.adminlogin.connectionsHeading, width: 140, dataIndex: 'ConnectionName'},
{header: Accero.Locale.text.adminlogin.connectionTypeHeader, width: 120, dataIndex: 'Type'}
],
loadMask: {
msg: Accero.Locale.text.adminlogin.loadingmask
},
viewConfig: {
stripeRows: true
}
}, config);
With these changes, I am getting the error at my local file 'ext-override.js' saying 'this.el is not defined'.
I debug the code and found that, in the current object this, there is no el object.
ext-override.js code:
(function() {
var originalInitValue = Ext.form.TextField.prototype.initValue;
Ext.override(Ext.form.TextField, {
initValue: function() {
originalInitValue.apply( this, arguments );
if (!isNaN(this.maxLength) && (this.maxLength *1) > 0 && (this.maxLength != Number.MAX_VALUE)) {
this.el.dom.maxLength = this.maxLength *1;
}
}
}
);
})();
Kindly suggest where am I going wrong?
Thanks in advance...

Answer 1

Seriously, use more lazy initialization! Your code is a hell of objects, all unstructured.
First of all, you can override and use the overridden method more easily with something like that (since 4.1)
Ext.override('My.Override.for.TextField', {
override : 'Ext.form.TextField',
initValue: function() {
this.callOverridden(arguments);
if (!isNaN(this.maxLength) && (this.maxLength *1) > 0 && (this.maxLength != Number.MAX_VALUE)) {
this.el.dom.maxLength = this.maxLength *1;
}
}
});
But: The method initValue is called in initField (and this in initComponent) so that you cannot have a reference to this.me because the component is actually not (fully) rendered.
So, this should help (not tested):
Ext.override('My.Override.for.TextField', {
override : 'Ext.form.TextField',
afterRender: function() {
this.callOverridden(arguments);
if (!isNaN(this.maxLength) && (this.maxLength *1) > 0 && (this.maxLength != Number.MAX_VALUE)) {
this.el.dom.maxLength = this.maxLength *1;
}
}
});
But I'm strongly recommend not to use such things within overrides. Make dedicated components which will improve code readibility.